Screw anti-loosening device for underwater nuclear pump and mounting and dismounting method of screw anti-loosening device

The invention discloses a screw anti-loosening device for an underwater nuclear pump and a mounting and dismounting method of the screw anti-loosening device, and belongs to the technical field of nuclear pump safety. The screw anti-loosening device can be remotely mounted and dismounted at a screw of the underwater nuclear pump, so that the screw is prevented from loosening and falling, time and labor are saved, the working efficiency is improved, the radiation dose of personnel is reduced, and the maintenance operation is safer and more reliable. The screw anti-loosening device comprises a dismounting and mounting platform and an anti-loosening mechanism, and is characterized in that the dismounting and mounting platform comprises a support, a piston sleeve, a supporting cylinder, a thrust rod, an elastic clamp holder and a locking sliding buckle, the support is provided with a blind hole, and an end cover is detachably arranged at the opening end of the blind hole of the support; and the piston sleeve is a